PR overview remains stuck checking mergeability after an UNKNOWN response

• Extension version: 0.166.0 and 0.167.2026091104 (pre-release)
• VSCode Version: 1.137.0
• OS: macOS 26.6.2 (25G83), arm64
• Repository Clone Configuration: Single repository
• GitHub Product: GitHub.com

Steps to Reproduce:

1. Open a repository containing an open pull request.
2. Open the pull request description from the GitHub Pull Requests view while GitHub reports its mergeability as UNKNOWN, such as immediately after creating or updating the pull request.
3. Scroll to the merge-status section and wait for GitHub to finish calculating mergeability.

Expected:

The extension polls again and replaces “Checking if this branch can be merged...” with the calculated mergeability status.

Actual:

“Checking if this branch can be merged...” remains indefinitely, even after GitHub.com and the GitHub API report the pull request as mergeable.

The polling code receives an object shaped like { mergeability, conflicts }, but passes the entire object to setMergeability():

const newMergeability = await checkMergeability();
setMergeability(newMergeability);

It should use:

setMergeability(newMergeability.mergeability);

Related: #4118 reported the same symptom but was closed before this response-shape regression was introduced.

Locate the polling code that calls checkMergeability() and setMergeability(), then inspect how the mergeability response is passed into the merge-status view. Update the handling so the calculated mergeability replaces the indefinite checking state, and verify the pull request overview updates after GitHub returns a resolved status.